1. Field of the Invention
The present invention relates to a head supporting mechanism for supporting a recording/reproduction use head that makes an access to a recording medium in an information recording apparatus.
2. Description of the Related Art
A head for recording/reproducing data on and from an information recording medium in an information recording apparatus such as a magnetic disk apparatus is installed on a slider that allows the head to float over the recording medium with a fine gap in between. A head supporting mechanism is used for supporting this head slider. The head supporting mechanism is attached to an actuator arm that is driven by a voice coil motor (VCM) serving as a driving source.
A suspension arm is attached to the actuator arm that is driven by the voice coil motor so as to freely pivot thereon, and the head slider is attached to the suspension arm. A fine-movement actuator utilizing a thin-film piezoelectric element is interpolated between the actuator arm and the suspension arm so that the suspension arm is allowed to pivot by driving the fine-movement actuator, thereby allowing the head on the slider to land on a track.
Great shifts such as a seeking operation of the head slider are carried out by controlling the voice coil motor, and the tracking compensation for landing-on a track is carried out by controlling the fine-movement actuator.
However, recent developments of high recording density in recording media and the resulting high-speed rotation of the recording medium have taken place so fast that it is sometimes difficult for the head supporting mechanism of the above-mentioned arrangement to follow the developments.
In the case of the head supporting mechanism having the above-mentioned arrangement, the entire suspension arm including the head slider is driven by the fine-movement actuator. However, the suspension arm is considerably long, and has a great mass with a great moment of inertia. For this reason, in the tracking compensation for positioning the head on a target track when the head is lifted off track, it is difficult to properly provide a high-speed response with high precision.